The downdraft gasification process has a number of advantages compared to the updraft gasification process, which is the process typically used in modern technologies for processing of carbon-containing feedstock. One such advantage of the downdraft gasification process is that process tars, acids and steam, which are formed in a low temperature pyrolysis zone, go through the combustion and reforming zones where, under the exposure to high temperatures, they reach almost a complete conversion into gasification gases. This makes it possible to use said gases for production of electric energy in gas-diesel engines, gas powered engines or gas turbines, for example, with minimal costs for cooling and purification of said gases.
At the same time, the traditional downdraft gasification process is characterized by some disadvantages that have prevented a more widespread use of that process. Some of the disadvantages of the traditional downdraft gasification process that have been described in the technical and scientific literature are: (1) the impossibility of use of the downdraft process for processing of plasticizing and coking feedstock with high content of volatile components due to the chocking-up of the feedstock in a bunker for drying and low temperature pyrolysis, which, in turn, results in an unstable gasification process followed by its complete shut-down; (2) the impossibility to operate with feedstock having fine or large fraction, feedstock representing aggregate pressed body, or feedstock with high ash content having low temperature of ash melting; (3) the necessity to shut-down the process for periodic loading or additional loading of feedstock, its manual crushing and pushing through (which is has been referred to as “poking”), (4) the need for periodic removal of residual ash and/or slag residue; (5) heterogeneity of v and compositions of the produced gases due to the stoppage for loading of the feedstock, which makes it more difficult to utilize such gases; (6) a low relative productivity of gasifiers caused by the air flow supply with parameters that do not allow to start the intensive slag formation process; (7) production of toxic inorganic ash residuals; (8) inability to effectively utilize the heat of the produced gases for improving the gasifier efficiency; and (9) significant heat losses.